net: Pick network device based on IP settings

The IP/netmask/gateway settings contain all informations
needed to pick the correct network device. This patch
adds support for that and makes specifying the "current"
network interface using the ethact command unnecessary.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 28 insertions, 2 deletions

diff --git a/net/net.c b/net/net.c
index 33d6e2c5b0..94954677c5 100644
--- a/net/net.c
+++ b/net/net.c
@@ -144,6 +144,27 @@ static void arp_handler(struct arprequest *arp)
 	}
 }
 
+struct eth_device *net_route(IPaddr_t dest)
+{
+	struct eth_device *edev;
+
+	for_each_netdev(edev) {
+		if (!edev->ipaddr)
+			continue;
+
+		if ((dest & edev->netmask) == (edev->ipaddr & edev->netmask)) {
+			pr_debug("Route: Using %s (ip=%pI4, nm=%pI4) to reach %pI4\n",
+			      dev_name(&edev->dev), &edev->ipaddr, &edev->netmask,
+				       &dest);
+			return edev;
+		}
+	}
+
+	pr_debug("Route: No device found for %pI4\n", &dest);
+
+	return NULL;
+}
+
 static int arp_request(struct eth_device *edev, IPaddr_t dest, unsigned char *ether)
 {
 	char *pkt;
@@ -154,6 +175,9 @@ static int arp_request(struct eth_device *edev, IPaddr_t dest, unsigned char *et
 	unsigned retries = 0;
 	int ret;
 
+	if (!edev)
+		return -EHOSTUNREACH;
+
 	if (!arp_packet) {
 		arp_packet = net_alloc_packet();
 		if (!arp_packet)
@@ -295,9 +319,11 @@ static struct net_connection *net_new(struct eth_device *edev, IPaddr_t dest,
 	int ret;
 
 	if (!edev) {
-		edev = eth_get_current();
+		edev = net_route(dest);
+		if (!edev && net_gateway)
+			edev = net_route(net_gateway);
 		if (!edev)
-			return ERR_PTR(-ENETDOWN);
+			return ERR_PTR(-EHOSTUNREACH);
 	}
 
 	if (!is_valid_ether_addr(edev->ethaddr)) {